It is known, in the case of bipolar power components, such as, for example, power diodes, power thyristors or power IGBTs, which have a comparatively weakly doped base zone, to provide in the base zone a stop zone doped more highly than the base zone. The stop zone serves, when the component is in the off state, for limiting the electric field propagating in the base zone and prevents a punch-through of the electric field to a more heavily doped emitter zone adjacent to the base zone. A power component having such a stop zone is described for example in DE 100 48 165 A1.
U.S. Pat. No. 4,517,582 describes a vertical power component having a stop zone arranged in a base zone at a distance from an emitter zone. Arranged between the stop zone and the emitter zone is an intermediate zone, in which the doping concentration decreases proceeding from the stop zone in the direction of the emitter zone down to the level of the doping concentration of the base zone.
A method for producing an n-doped stop zone in a semiconductor body is described in DE 102 43 758 A1. This method involves radiating protons into the region of the semiconductor body in which the stop zone is intended to be produced. This irradiation step is followed by a thermal method in which the semiconductor body is heated to temperatures of between 250° C. and 550° C. for a time duration of between 1 minute and 250 minutes in order to generate hydrogen-induced donors.
When bipolar power components are turned off, it is advantageous, in principle, if the temporal gradient of the current flowing in the base zone is as small as possible toward the end of the turn-off phase, that is to say if the current flowing in the base zone decreases as gently as possible. Voltages which are induced during the turn-off operation in supply leads to the component at parasitic leakage inductances that are unavoidably present can thereby be minimized.